Thermostatically controlled fan



oct. 3o, 1934 c. FURGASON 1,978,788'

THBRMOSTATICALLY CONTROLLED FAN Filed Aug. 18. 1930 Patented oct. 3o, 1934 l PATENT OFFICE THERMOSTATICALLY coN'rRoLLED FAN Claude E. Furgason, Lansing, Mich., assgnor to Reo Motor Car Company, Lansing, Mich., a corporation of Michigan Application August 18, 1930, Serial No.-476,219

2 Claims.

This invention relates to cooling systems for motor vehicles and the like and more particularly to a thermostatically controlled fan of the type usually employed in the cooling systems` of inter- 5 nal combustion engines for motor vehicles.

AIn circulatory cooling systems for the engines of motor vehicles it is customary to provide a fan arranged Vbetween the motor and water cooling radiator for drawing-air through the radiator to assist in the dissipation of the heat. However, it is also customary to provide shutters with various types of control mechanism whereby the passage of air through lthe radiator is cut off or checked, particularly in cold weather, until the motor temperature has reached a predetermined degrec. VHowever, with the use of shutter mechanismsl with radiators it is still generally customary to drive the fan and have the fan exert its maximum eiort to draw air through the radiator. Y This is inefcient because the action of the fan tends to counteract the control which the shutters afford for the passage of air through the radiator., V

It is therefore one of the important objects of this invention to provide a thermostatically controlled fan, the blades of which may be rotated' tails of construction of the invention will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawing, wherein Figure lis a fragmentary sectional elevational view through a motor vehicle engine showing a cooling fan associated therewith constructed in accordance with my invention, and

Figurev2 is an enlarged fragmentary sectional view taken substantially onthe plane indicated by line 2-.2 in Figure 1.

Referring now'to the drawing wherein like reference characters indicate like parts, there is il- '1ustrated a fragment'of a motor vehicle engine 10 on the forward end of which a cooling fan indicated generally by the 'reference character 11 isv mounted. 710 the hub 12 of the fan there is attached a pulley 13 with which the ordinary 5'5 fan belt (notI shown) engages for rotating the (Cl.l 1870-163) fan. The fan is rotatably journaled on a bracket 14 projecting from the front of the engine 10.

As shown, the hub 12 of the fan is fashioned with a pair of parallel openings for rotatably receiving the shafts 16 which carry the fan blades 60 15 and the shafts are secured therein by means of bolts. Each fan blade l5 is unbalanced with respect to its shaft 16. In other words, the shaft 16 of each fan blade is offset from the longitudinal center of the fan blade to provide a relatively narrow portion 15Et arranged on one side of the longitudinal centerv of the fan and a relatively wide portion 15b arranged on the other side of the longitudinal center of the fan blade. The shaft 16 of each fan blade is normally free to rotate in the hub 12 so that by reason of the unbalanced condition of each fan blade, the wider section 15b drags or trails when the fan is rotated to thus so feather the blades that rotationfof the fan will not causeair to be drawn through the radiator. This is the position of the fan blades when the motor is started and when the temperature thereof is below a predetermined point.

Extending through the shaft 17 of the fan is a rod 18 the rear end of which is adapted to be engaged by a thermostatic element 19. This thermostatic element may be of any preferred or desired design and is preferably responsive to temperature changes in the motor 10. For this purpose it may be conveniently located within or 5 in juxtaposition to a water passage 20 of the circulatory cooling system of the motor. As the temperature rises in the motor the thermostatic element 19 expands and exerts an endwise pres'- sure on the rod 18 whichwill slide the same longi- 90 tudinally of the shaft 17 and cause the attened end 21 thereof to engage against the corners of Aflattened surfaces 22 on the blade shafts 16. This pressure of the rod 18 on the blade shafts 16 causes a rotative movement Vthereof so as to bring the flattened surfaces 22 in to surface engagement with the flattened end 21 of the rod 18. This rotative movement of the blade shafts 16 causes a rotative movement of the blades to feather the bladesand cause them to assume substantially the position illustrated in Figure 1 in which they will cause air to be drawn through theradiator of the motor vehicle. Obviously, as the'temperature of the motor increases the blades will be feathered from the position in which they are rotated flatwise to the completely feathered position in Figure 1. When in this latter position the fan will obviously exert its maximum action and will cause a maximum amount of air to be drawn through the radiator.

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It is obvious that if the motor is started in a cool condition and the fan blades are rotated latwise so that no air is drawn through the radiator by the fan that the motor will heat up more quickly and thus more quickly attain the desired temperature. As the motor attains this desired temperature,l the feathering action heretofore referred to will take place so that the fan will become eiective to cool lthe radiator and as a consequence the motor and to maintain the motor at this desired temperature.

Obvious modiiications will suggestthemselves to those skilled in this art and tothis end reservation is made to make such changes as may come within the purview of the accompanying claims.

What I claim as my invention is:

1. A motor vehicle cooling fan comprising a hub, a fanblade shaft rotatively mounted in said hub, a blade carried by said shaft and attached thereto at one side of its longitudinal center whereby said blade is unbalanced, said shaft having an angular portion providing acorner, a temperature responsive means, a rod slidable end- Wise upon expansion of the temperature responsive means, and means on said rod engageable with said corner to rotate said blade shaft, for the purpose set forth. y

2. A motor vehicle cooling fan comprising a hub having a pair of parallel openings/therein, fan blade shafts rotatively mounted in said openings, a fan carried by each of said shafts and attached thereto at one side of its longitudinal center whereby said blade is unbalanced, said shafts each having a ilattened portion providing a corner, a temperature responsive means, a rod slidable endwise upon expansion of said temperature responsive means, and an end on saidv rodengageable with said corner to rotate said blade shaft, for the purpose set forth.-

E. FURGASON.

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